The Effect of Gamma Radiation on Protein Structure and Dynamics

Abstract

Gamma radiation being the most energetic form of electromagnetic radiation has applications in number of different fields such as in medicine for treating cancer, food sterilization and in astronomy for studying phenomenon like gamma ray bursts. However, the mechanism of action or the residue wise information of the effects of gamma radiation is lacking. Also, most of the research in this direction has been to study the effects on DNA. But cells contain other biomolecules also and so we took up protein molecule for our study. The study on the effect of gamma radiation on proteins could form an essential part in our understanding of how it changes the structure of these biomolecules which could help us in explaining how it is able to cure cancer or could provide answers to questions like how life originated on earth and the possibility of existence of extraterrestrial life. In this thesis, with this objective, we have tried in unraveling some of the effects of gamma radiation on proteins with the spectroscopic techniques of NMR and Mass. The first chapter gives a brief overview of the gamma radiation overall and explains some of the research work done previously by others along with introducing the techniques of NMR Spectroscopy and Mass Spectrometry which we have used for the first time to perform the studies. NMR being one of the most sensitive techniques in providing atomic level details in proteins has been used extensively to study the effects. The second chapter deals with the effect of gamma radiation on one such protein Ubiquitin. Since, Ubiquitin is a very stable protein and also it is involved in the cancer metabolic pathway, the effect of gamma radiation on Ubiquitin was taken up for the study. The outcome of the study is that gamma radiation has a dosage and sample dependent effect on the protein. Ubiquitin as a globular protein in its pure form in showed no observable effect at low dosage of irradiation that is being used for cancer treatment. However, at higher dosage of radiation, there were substantial changes in the structural and dynamical properties of the protein which is discussed in details in the thesis.